Fuel screening discharge nozzle for oil burners



July 1, 1952 w. FAHRBACH 2,602,006

FUEL scRgENNG DISCHARGE NoZzLE FOR OIL BURNERS Filed Nov. 1, 195o l INVENTOR. fifi/12,2; w27; Fzza: c, B

Patented July 1, 19 52 FUEL SCREENING DISCHARGE NozzLE Fon on. BUENERS William Fahrbach, Maplewood, N. J.

Application November 1, 1950, Serial No. 193,502

2 Claims. (Cl. 299-120) The invention relates to oil burners and has particular reference to an improved fuel screening nozzle therefor.

Prior to the present invention, oil burner nozzles have been provided with various types of mesh screens through which the fuel oil must pass in going from the supply pipe to the discharge orice at the burner tip for the purpose of arresting any solidparticles that may be suspended in the fuel. These screens have been so constructed and arranged that the fuel penetrates transversely or at right angles to the plane of the screen, and thus has frictional contact therewith throughout a distance only equal to its thickness. As a consequence of this, particles often squeeze through and reach the discharge orifice to clog the same and thereby choke the burner name.

It is the primary object of the invention to improve upon the existing inefficient discharge nozzles by providing a sleeve-type screen of woven mesh which is incorporated and confined in the nozzle construction in such a manner that the fuel must weave longitudinally through the interstices of the mesh in its passage to the discharge orifice. These interstices are as long as the screen instead of being equal only to its thickness, which multiplies the distance of frictional contact.

Since the usual screen arrangement, through which the fuel passes transversely, is useful in arresting the larger solid particles, it is proposed to utilize a screen so arranged as a primary screen and to add a secondary woven mesh screen related to means for confining fuel passage to movement longitudinally through its interstices, i. e. along the plane thereof. Furthermore, since longitudinal penetration of woven mesh is more readily accomplished when the fuel oil has been thinned by heating, the secondary screen is located closer to the discharge orifice than the primary screen in order that heat from the burner tip may be conducted to the said secondary screen through the metallic mass of the nozzle.

Other objects and advantages will become apparent as the following specific description is read in connection with the accompanying drawing, in which:

Fig. 1 is a fragmentary side elevation, partly in section, of an oil burner nozzle constructed in accordance with the invention;

Fig. 2 is a longitudinal cross-sectional view of the same; and

Fig. 3 is a transverse section on line 3-3 of Fig. 2.

Referring in detail to the drawing, wherein like reference characters designate corresponding parts in the several views, the reference character I0 indicates the nozzle head, which has screw-threaded detachable connection with the outer end of fuel supply pipe II. Nozzle head Ill is axially bored to provide a cylindrical chamber I2, which has a tapered seat I3 formed at its outer end and a central discharge orifice I4 leading outward through burner'tip I5 from the apex of said seat. The outer portion of chamber I2 adjacent to seat I3 is smooth-surfaced, whereas its inner portion is screw-threaded for engagement by the screw-threaded base portion of a cylindrical plug I6, which plug is completely contained within said chamber, and also for detachable reception of the externally screwthreaded open end of a thimble I'I.

Thimble I'I projects into the fuel supply pipe II, and is reduced in diameter relative to the internal diameter of said supply pipe. Thimble II has a plurality of lateral apertures I8, and supports the usual rscreen sleeve I9 in covering relation to said apertures. This screen sleeve I9, whichwill be termed the primary screen, is intended to arrest solid particles suspended in the fuel oil as it flows from the supply pipe II radially inward through apertures I8 and thence upwardly out of the thimble interior. For this primary screen, it may be practicable to employ some type of mesh other than the Woven type shown. It is also within the scope of the invention to adopt some shape other than that of a cylindrical sleeve.

Plug I6 has an outer portion I6 of reduced diameter to provide a smooth cylindrical peripheral surface concentric'to the internal side wall surface of chamber I2 of head Ill, its diameter being such that an annularspace 20 is formed between said surfaces. This annular space 20 shouldbe of just the precise radial extent or width to accommodate the thickness of a screen sleeve 2l of woven mesh for snug nt therein. Screen sleeve 2| will be known herein as the secondary screen of the combination.

In order to permit passage of fuel from the interior of thimble I1 to the inner end of annular space 20, plug I6 is provided with a peripheral groove 22 immediately forward of the screwthreaded base portion thereof, and with at least one longitudinal groove 23 extending endwise through said base portion. Passage of fuel from annular space 20 Ato discharge orifice I4 is provided for by a further reduction in diameter of the terminal portion I6" of plug I6'-I6' just beyond said space 20 to form an annular channel 24 adjoining tapered seat I3, and by the further provision of grooves 25 in the end face 28 of the terminal portion I6", which latter is shaped to engage said seat I3. Grooves 25 have been arranged in the usual manner tangential to discharge orifice I4 in order to impart swirling atomizlng motion to the issuing fuel iet.

In the operation ofthe improved nozzle, when the fuel stream reaches groove 224at the inner end of annular space 20, it will be forced to penetrate the longitudinally extending interstices of secondary screen 2 l, and thus to ow lengthwise of said screen. These interstices are both tortuous and smaller in cross-section than the transverse interstices, which is anadvantage because any solid particles that may have escaped through primary screen I9 will be arrested by said secondary screen. The fuel is thus required Y to weave back and forth between and across the wires of the screen meshand between the screen and the confining wall surfaces of the nozzle head l0 and theV plug portion I6', as it flows from the inner end of secondary screen 2l through to the outer end thereof. During this tortuous passage of the fuel, any solid particles remaining in suspension therein will be in frictional contact with said wires and surfaces and will be subjected to the constant retarding effect of such contact, with the practical certainty that they will eventually become lodged against some obstructing shoulder or wire intersection of the screen mesh, or become wedged securely between some relatively opposed surfaces. The result will be very erlicient screening of even the finest particles from the uid stream. Due to the close proximity of secondary screen 2l to burner tip l5, heat conducted inwardly from said tip through the metallic mass of nozzle head l0 and of plug I6 to the region of annular space 20 will thin the fuel and thereby improve its screen penetrating ability.

In order to clean both screens, all that is necessary is to unscrew nozzle head l0 from supply pipe Il, unscrew thimble Il from said nozzle head, and remove plug I6 from said nozzle head also by unscrewing the same. When this has been done, both screens are readily separable from their applied positions. v

It should be apparent that the complete nozzle is very compact in form, simple in construction and composed of a minimum number of parts, as well as being of high eliiciency in its fuel cleaning capacity.

Having thus described the invention, I claim:

1. A discharge nozzle for oil burners comprising a. nozzle head adapted for connection to a fuel supply pipe and having a burner tip, said nozzle head being provided with a cylindrical chamber and a central discharge orice leading therefrom through the burner tip. a cylindrical nular space and from the latter outward to the discharge orifice, and a secondary screen in the form of a woven mesh sleeve tted snugly in said annular space, whereby fuel passing through said space toward the discharge orifice must Weave longitudinally through the interstices of the woven mesh. r

2. A discharge nozzlefor oil burners comprising a nozzle head 4adapted for connection to a fuel supply pipe and having a burner tip, a primary fuel screening means intermediate the interior of the supply pipe and said nozzle head, said nozzle head being provided with a cylindrical chamber beneath the burner tip. said burner tip having a central discharge orifice leading'outwardly from said chamber, a cylindrical plug within the chamber of said nozzle head, said plug being of less diameter than the internal diameter of said chamber whereby to provide an intermediate annular space, said plug having a fuel passageway through which fuel from the primary fuel screening means flows into said annular space and from said space outwardly to the discharge orifice, and a tubular woven metallic mesh screen filling said annular space so as to span the same, whereby fuel passing through said space toward the discharge orifice must weave longitudinally through the interstices of said woven mesh screen.

` WILLIAM FAHRBACH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name o Date `858,092 Millor June 25, 1907 918,005 Charonne Apr. 13, 1909 1,204,051 Millbourn Nov. 7,1916

1,879,938 Lambert Sept. 27, 1932 2,120,611 Huss June 14, 1938 2,321,428 Schloz June 8, 1943 FOREIGN PATENTS Number Country 4 Date 344,209 Great Britain ;Mar. 5, 1931 

